JPH07217811A - Boiler - Google Patents

Abstract

PURPOSE:To obtain a boiler in which a size can be reduced and a heat transfer tube can be rigidly supported. CONSTITUTION:A front side coupler 37a and a rear side coupler 37b are provided inside a front side horizontal supporting plate 31a and a rear side horizontal supporting plate 31b, the coupler 37a is coupled to the coupler 37b via a coupling rod 38 to integrally form a front side heat transfer tube 27a with a rear side heat transfer tube 27b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boiler apparatus, and more particularly to a horizontal support structure for a boiler heat transfer tube which is suitable for preventing deformation of a vertical heat transfer tube due to exhaust gas flow pressure, an earthquake or the like.

[0002]

2. Description of the Related Art A large-capacity thermal power plant has been constructed to meet a rapidly increasing power demand, but these boilers are required to perform a transformer operation in order to obtain a high power generation efficiency even at a partial load. ing.

This is a feature of the recent demand for electric power, and as the nuclear power generation grows, the difference between the maximum load and the minimum load also increases.
Thermal power generation tends to shift from base load to load adjustment.

In other words, when operating thermal power generation for load adjustment, few boiler loads are always operated at full load, and the load is increased or decreased to 75% load, 50% load, 25% load. The so-called daily start / stop (Daily Start)
By carrying out an operation such as an operation such as Stop (hereinafter, simply referred to as DSS), the DSS operation is performed only in the daytime when the power demand is high, and the operation is stopped at night to improve the power generation efficiency.

For example, as a part of high-efficiency power generation, a combined gas turbine plant has recently attracted attention. In this combined gas turbine plant, power is first generated by the gas turbine, and the exhaust heat in the exhaust gas discharged from the gas turbine is recovered by the exhaust heat recovery boiler and steam generated by the exhaust heat recovery boiler is used. Then, it operates a steam turbine to generate electricity.

As described above, in the combined gas turbine plant, since the power generation by the gas turbine and the power generation by the steam turbine are simultaneously performed, the power generation efficiency is high and the load response characteristic of the gas turbine is excellent. It can cope with the rise and fall of demand, and is excellent in load followability, which is convenient for DSS operation.

An outline of the exhaust heat recovery boiler will be described below with reference to FIG.

FIG. 8 is a vertical sectional view of the exhaust heat recovery boiler.

A secondary superheater 4, a primary superheater 5, an evaporator 6 and a economizer 7 are arranged in the exhaust gas passage 3 surrounded by the flues 1 and 2 from the upstream side to the downstream side of the exhaust gas G. .

In such a structure, water introduced from a water supply pump (not shown) enters the economizer inlet inlet 9 of the economizer 7 through the water supply pipe 8 and rises in the economizer pipe 10. Collected by the economizer outlet outlet 11, descends the economizer connecting pipe 12, and enters the economizer inlet inlet 9 located on the upstream side of the exhaust gas G. The water that has flowed out of the economizer outlet header 11 on the gas upstream side by sequentially repeating this upflow and downflow is the drum water supply pipe 1.
Enter steam drum 14 through 3. The water in the steam drum 14 passes through a precipitation pipe 15 and a water supply pipe 16 and enters an evaporator inlet header 17 and an evaporator pipe 18 of the evaporator 6, and again passes through an evaporator outlet header 19 and an ascending pipe 20 to be vaporized again. It returns to the drum 14. On the other hand, the steam separated from the steam in the steam drum 14 passes through the superheater inlet connection pipe 21 and enters the primary superheater inlet pipe 22 of the primary superheater 5, and the primary superheater pipe 23 and the primary superheater outlet pipe 22. The secondary superheater pipe 27 of the secondary superheater 4 is led to the secondary superheater inlet pipe head 26 of the secondary superheater 4 through the desuperheater 25 for controlling the temperature of the superheated steam.
In the process in which the fluid inside the pipe rises and falls, it is superheated to a predetermined temperature and is collected in the outlet port 28 of the secondary superheater to collect the main steam pipe 2
9 leads to a steam turbine (not shown).

The bottom support structure of the heat transfer tube will be described below with reference to FIG.

As shown in FIG. 8, the heat transfer tube group of the economizer tube 10, the evaporator tube 18, the primary superheater tube 23, and the secondary superheater tube 27 that exchange heat with the exhaust gas G have excellent heat recovery. , It uses a finch uve with a good space factor and is arranged in a staggered arrangement.

The heat transfer tube group is started and stopped daily (DS
S) In order to quickly respond to the operation, a coal economizer inlet header 9, an evaporator inlet header 17, a primary superheater outlet header 24, a secondary superheater inlet header 26 and a secondary heater are provided at the bottom of the heat transfer tube group. A secondary superheater outlet pipe header 28 is provided so that the drain in the heat transfer pipe group accumulated during the stop can be discharged.

In this way, as shown in FIG. 8, in the heat transfer tube, the secondary superheater inlet pipe head 26 and the secondary superheater outlet pipe head 28 are supported by the bottom wall of the flue 2 via the support metal fittings 30. There is.

Accordingly, the heat transfer tube is the secondary superheater inlet tube assembly 2
6. Thermal expansion is performed upward from the outlet port 28 of the secondary superheater. Therefore, the secondary superheater tube 27 is provided with four rows of heat transfer tubes because it is superheated to a predetermined temperature. However, heat exchange with the exhaust gas G is performed on the gas upstream side and the gas downstream side of the heat transfer tube. , The steam temperature in the heat transfer tube is different.

That is, the steam temperature of the heat transfer tube located on the upstream side of the exhaust gas G is high, and accordingly, the metal temperature of the heat transfer tube on the upstream side is higher. Therefore, thermal stress that restricts the thermal expansion difference is generated in the heat transfer tubes on the exhaust gas upstream side and the downstream side,
The horizontal portion of the ceiling portion of the secondary superheater 4 is elongated so that the horizontal portion has flexibility so as to absorb the difference in thermal expansion.

As a result, a space is required between the heat transfer pipes on the gas upstream side and the gas downstream side, so that the entire length of the boiler apparatus becomes long, and the flues 1 and 2 become long, resulting in an increase in cost. Invite. Furthermore, no matter how much horizontal part is provided on the ceiling of the secondary superheater 4 to give flexibility, the stress generation due to the difference in thermal expansion cannot be eliminated, and particularly in the combined power generation plant,
Frequent start-stop operation causes fatigue failure.

As another example of the prior art, a suspension structure for suspending a heat transfer tube as shown in FIGS. 9 to 11 will be described.

FIG. 9 is a side view of the secondary superheater, and FIG. 10 is FIG.
11 is an enlarged sectional view taken along line AA of FIG. 11, and FIG. 11 is an enlarged sectional view taken along line BB of FIG.

9 to 11, 3 is an exhaust gas passage, 4 is a secondary superheater, 26 is an inlet pipe, 28 is an outlet pipe, 7a and 27b are a front heat transfer pipe and a back heat transfer pipe, 31a and 31b are front-flow side horizontal bundles (front-flow side horizontal support plate) and back-flow side horizontal bundles (back-flow side horizontal support plate), 32 is a horizontal support, 33 is a heat transfer tube support, 3
4a and 34b are a front flow side band and a back flow side band, 35
a and 35b are front-flow-side connecting lugs and back-flow-side connecting lugs, 3
6a and 36b are a front flow side pin and a back flow side pin.

In such a structure, the upstream heat transfer tube (the upstream secondary heat exchanger tube) 27a and the downstream heat transfer tube (the downstream flow) vertically arranged in the flues 1 and 2 through which the exhaust gas G flows. The side secondary superheater pipe) 27b is, as shown in FIG.
The front flow side and the back flow side heat transfer tubes 27a and 27b are provided with front flow side and back flow side horizontal support plates 31a and 31b in several stages, respectively.

However, even if the upstream heat transfer tube 27a is supported by the upstream support plate 31a and the downstream heat transfer tube 27b is supported by the downstream support plate 31b, the upstream heat transfer tube 27 and the downstream heat transfer tube 27 are supported.
Since a and 27b each have two rows and low rigidity,
0, it is necessary to connect with a horizontal support 32 as shown in FIG.

That is, as shown in FIGS. 10 and 11, the front flow side band 34a and the back flow side band 34b are attached to the front flow side and the back flow side heat transfer tubes 27a and 27b, respectively.
The upstream side connecting lugs 35a are connected to the downstream side bands 34a and 34b,
The downstream lug 35b is attached by welding.

Then, the front-side and rear-side connecting lugs 35
As shown in FIGS. 10 and 11, the horizontal support 32 is arranged between a and 35b, and the front-flow-side connecting lug 35a and the horizontal support 32 are connected to the rear-flow-side connecting lug 35 by the front-flow-side pin 36a.
By connecting b and the horizontal support 32 by the backflow side pin 36b, the frontflow side heat transfer tube 27a and the backflow side heat transfer tube 2 are connected.
It increased the rigidity of 7b.

However, in order to mount the horizontal support 32 between the front heat transfer tube 27a and the rear heat transfer tube 27b, both connecting lugs 35a, 35b are connected to the pins 36a, 36.
It is necessary to connect with b. For this purpose, the heat transfer tube 2 on the upstream side is connected.
It is necessary to secure a work space in which a worker enters between the 7a and the heat transfer pipe 27b on the downstream side to work.

Therefore, the entire boiler apparatus becomes large,
The flues 1 and 2 become long, resulting in cost increase.

Further, the secondary superheater 4 is supported by the upper heat transfer tube support 33 at two positions, front and rear, and the single band type support cannot be used.

[0028]

In the heat transfer tube support structure of the prior art, a work space for mounting a horizontal support between the heat transfer tube groups is required, which results in an increase in the size of the boiler device, which in turn increases the size of the heat transfer tube. There is a drawback that the built-in flue becomes long and the cost increases economically.

The present invention is intended to solve the drawbacks of the prior art, and an object thereof is to obtain a boiler device which can downsize the boiler device and firmly support the heat transfer tube group. Is.

[0030]

In order to achieve the above-mentioned object, the present invention provides connecting fittings inside the horizontal support plate on the front flow side and the horizontal support plate on the downstream flow side, and connects the connecting metal fittings with a connecting rod. Then, the heat transfer tube on the upstream side and the heat transfer tube on the downstream side are integrated.

[0031]

[Function] Since the front flow side horizontal support plate and the back flow side horizontal support plate can be integrally formed with the connecting rod from the side without an operator entering between the front flow side heat transfer pipe and the back flow side heat transfer pipe. , The boiler device can be made smaller accordingly.

[0032]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a transverse sectional view of a boiler apparatus according to an embodiment of the present invention, which is an enlarged sectional view taken along the line CC of FIG. 3, FIG. 2 is a side view taken along the line DD of FIG. 1, and FIG. It is a whole block diagram of a superheater.

1 and 3, reference numerals 4 to 31
Up to shows the same as the conventional one.

37a and 37b are horizontal support plates 31 on the upstream side.
a, a front-flow-side connecting metal fitting and a rear-flow-side connecting metal fitting mounted on the inner side of the rear-flow-side horizontal support plate 31b by welding or the like, and a connecting rod 38 connecting the front-flow-side connecting metal fitting 37a and the rear-flow-side connecting metal fitting 37b. , 39 are welded portions that prevent the connecting rod 38 from falling off.

In such a structure, the inlet header 2
6, the outlet pipe header 28 is connected by a front heat transfer pipe 27a and a rear heat transfer pipe 27b bent in an inverted U shape as shown in FIG. 3, and the heat transfer pipes 27a, 27b are supported by the heat transfer pipes. Bend along 33.

The front heat transfer tube 27a and the rear heat transfer tube 27b are, as shown in FIGS.
7a is a horizontal support plate 31a on the upstream side, so that the heat transfer tube 2 on the downstream side is
7b is supported by a wake side horizontal support plate 31b.

However, the two rows of heat transfer tubes 27a, 27
Since b is only a bundle-shaped support of the horizontal support plates 31a and 31b, it is weak in strength against vibration such as an earthquake. Therefore, as best shown in FIG. The front-flow-side connecting metal fitting 37a is attached by welding to the inside of the backflow-side horizontal support plate 31b, and the backflow-side connecting metal fitting 37b is attached to the inside of the rear-flow-side horizontal support plate 31b by welding.
By connecting 7b comrades with a connecting rod 38, a seismic resistant structure is formed.

That is, the secondary superheater 4 is laid down in the horizontal position and the horizontal support plates 31a and 31b are attached thereto, and then the connecting rod 38 is moved from the left side to the right side in FIG.
The connection fittings 37b, 37a, 37b, 37a are sequentially connected.

At the right end of FIG.
A and the connecting rod 38 are fixed at the welded portion 39 to prevent the connecting rod 38 from coming off.

As described above, the horizontal support plates 31a and 31b supporting the heat transfer tubes 27a and 27b are connected to the connecting fittings 37a and 37a.
By making the 37b and the connecting rod 38 into an integrated structure, a seismic resistant structure can be obtained, and the connecting fittings 37a, 37b
Since the comrades can be made into an integral structure by inserting the connecting rod 38 from the side surface of the secondary superheater 4, the work space between the heat transfer tubes 27a and 27b as in the conventional case is unnecessary, and only that. The boiler device itself can be downsized.

FIGS. 4 to 7 show another embodiment. FIG. 4 is a transverse sectional view of the boiler apparatus, an enlarged sectional view taken along the line EE of FIG. 7, and FIG. 5 is a sectional view taken along the line F- of FIG. F line side view, FIG. 6 is FIG.
GG line side view, FIG. 7 is an overall configuration diagram of the secondary superheater.

4 to 7, reference numerals 4 to 38 are the same as those in FIGS. 1 to 4.

Reference numerals 40a and 40b denote horizontal support plates 31a and 31.
front-side support lugs and back-side support lugs attached to b, 41 horizontal supports, 42 brackets, 4
3 is a color.

The difference between the embodiment shown in FIGS. 1 to 3 and the other embodiment shown in FIGS. 4 to 7 is that in the embodiment shown in FIGS. While the front heat transfer pipe 27a and the rear heat transfer pipe 27b are integrally formed by the connecting rod 38, the front heat transfer pipes and the back heat support lugs are different in FIGS. 4 to 7. 40a, 40b, the horizontal support 41, the bracket 42, and the collar 43 constitute a connecting fitting, and these connecting fittings are integrally formed by the front and rear connecting rods 38a, 38b.

The method of assembling the horizontal support 41 will be described below.

Front heat transfer tube 27a, Back heat transfer tube 27b
Are alternately stacked in parallel with the horizontal support plates 31a and 31b which are orthogonal to each other, and the front heat transfer tubes 27a and 27b are connected to the front heat transfer tubes 27a and 27b.
Are assembled in bundles into two rows of tubes.

Front-side and rear-side support lugs 40a, 40
In the process of assembling the horizontal support plates 31a, 31b, b is attached to the horizontal support plates 31a, 31b by welding, with the horizontal support 41 facing the insertion space portion.

The horizontal support 41 leans against the upper surface of the heat transfer pipe 27b on the downstream side, and the support lug 40a and the bracket 42 are provided.
4, the front side connecting rod 38a is inserted from the side portion of the secondary superheater 4 into the pin hole, and the horizontal support 41 is set.

The horizontal support 41 is attached to the horizontal support plate 31b so that the bracket 42 at the center of the panel is sandwiched so that the horizontal support 41 does not come out in the left-right direction.
The collar 43 is inserted in the gap with b. Incidentally, the collar 43 is penetrated when the wake side connecting rod 38b is inserted.

Next, the heat transfer tube 27a on the upstream side is placed on the horizontal support 41. Similarly to the above, from the side portion to the upstream connecting rod 38
Insert a. In this case, the tips of the connecting rods 38a and 38b are tapered so that they can easily enter the pin holes.

Finally, the connecting rods 38a, 38b are fixed to the outermost bracket 42 by the welded portion 39 so as not to come off.

As described above, the horizontal support 41 is provided on the upstream side,
Horizontal support plates 31a, 31 for the downstream heat transfer tubes 27a, 27b
By connecting with b, the rigidity of the secondary superheater 4 as a whole can be increased and a seismic resistant structure can be obtained.

[0054]

According to the present invention, the boiler device can be downsized and the heat transfer tube can be firmly supported.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a boiler device according to an embodiment of the present invention.

FIG. 2 is a side view taken along the line DD of FIG.

FIG. 3 is an overall configuration diagram of a secondary superheater.

FIG. 4 is a cross-sectional view of a boiler device showing another embodiment.

5 is a side view taken along line FF in FIG.

FIG. 6 is a side view taken along line GG in FIG.

FIG. 7 is an overall configuration diagram of a secondary superheater.

FIG. 8 is a vertical sectional view of an exhaust heat recovery boiler.

FIG. 9 is a side view showing a suspension structure of a conventional heat transfer tube.

10 is an enlarged cross-sectional view taken along the line AA of FIG.

11 is an enlarged cross-sectional view taken along the line BB of FIG.

[Explanation of symbols]

 26 inlet pipe header 28 outlet pipe header 31a front side horizontal support plate 31b rear side horizontal support plate 37a front side connecting metal fitting 37b rear flow side connecting metal fitting 38 connecting rod

Claims (1)

[Claims] 1. An inlet pipe outlet, an outlet pipe header, and an inlet pipe header and an outlet pipe header are connected by a front flow side heat transfer tube and a back flow side heat transfer tube curved in an inverted U shape, The side heat transfer tubes are supported by the front flow side horizontal support plate and the back flow side heat transfer tubes are supported by the back flow side horizontal support plate, respectively, and are connected to the inside of the front flow side horizontal support plate and the back flow side horizontal support plate. A boiler device characterized in that a metal fitting is provided, and the connecting metal fittings are connected by a connecting rod so that the front heat transfer tube and the rear heat transfer tube are integrated.